The new definition will increase the number of people counted as rape victims in FBI statistics.

WASHINGTON — The Obama administration on Friday expanded the FBI's more than eight-decade-old definition of rape to count men as victims for the first time and to drop the requirement that victims must have physically resisted their attackers.

The new definition will increase the number of people counted as rape victims in FBI statistics, but will not change federal or state laws nor alter charges or prosecutions.

The expansion has been long awaited because policymakers and lawmakers use crime statistics to allocate resources for prevention and victim assistance.

Senior White House adviser Valerie Jarrett called the change a "very, very important step." The issue got top-level White House attention starting last July, when Vice President Joe Biden raised it at a Cabinet meeting.

Biden, author of the Violence Against Women Act when he was in the Senate, said the new definition is a victory for women and men "whose suffering has gone unaccounted for over 80 years." Calling rape a "devastating crime," the vice president said "we can't solve it unless we know the full extent of it."

Since 1929, the FBI has defined rape as the carnal knowledge of a female, forcibly and against her will. The revised definition covers any gender of victim or attacker and includes instances in which the victim is incapable of giving consent because of the influence of drugs or alcohol or because of age. Physical resistance is not required. The Justice Department said the new definition mirrors the majority of state rape statutes now on the books.

Senate Judiciary Committee Chairman Patrick Leahy, D-Vt., said all rape victims "should have access to the comprehensive services that will help them rebuild their lives."

In November, Leahy introduced legislation to reauthorize the Violence Against Women Act and provide an increased emphasis on efforts to stop sexual assault.

"We've always had a broad definition of who is eligible for services and the change could result in additional resources being made available for survivors of rape," said Linda McFarlane, deputy executive director of Just Detention International. The nonprofit human rights organization works to eliminate sexual abuse in prisons and other detention settings.

Using the old definition, a total of 84,767 rapes were reported nationwide in 2010, according to the FBI's uniform crime report based on data from 18,000 law enforcement agencies.

Nearly 1 in 5 women and 1 in 71 men in the U.S. have been raped at some time in their lives, according to a 2010 survey by the National Center for Injury Prevention and Control of the Centers for Disease Control and Prevention, which used a broader definition.

The revised FBI definition says that rape is "the penetration, no matter how slight, of the vagina or anus with any body part or object," without the consent of the victim. Also constituting rape under the new definition is "oral penetration by a sex organ of another person" without consent.